Hello All,
I am developing application in which I am using List view and for that list
I am using a cursor adapter.
I have an sqlite file in assets/databases which is used for reading data and
create database.
I created database. For cursor adapter I am getting cursor from this
database.
Here is my code
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
/**
* @author Renuka A.
*
*/
public class DataBaseHelper extends SQLiteOpenHelper{
//The Android's default system path of your application database.
private static String DB_PATH =
"/data/data/com.praumtech.names4baby/databases/";
private static String DB_NAME = "newdata";
private static String DB_FILE_NAME = "newdata.sqlite";
private SQLiteDatabase _database;
public static int ALL_NAMES = 0;
public static int FAVORITE_NAME = 1;
private String FAVORITE_TABLE = "favmaster";
private String NAME_MASTER_TABLE = "namemaster";
private final Context _context;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access
to the application assets and resources.
* @param context
*/
public DataBaseHelper(Context context) {
super(context, DB_NAME, null, 1);
_context = context;
}
/**
* Creates a empty database on the system and rewrites it with your own
database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
Log.d("Exception", " checkDataBase "+dbExist);
if(dbExist){
//do nothing - database already exist
try {
String myPath = DB_PATH + DB_NAME;
_database = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
Log.d("Exception", " create database to open databse ");
} catch (Exception e) {
e.printStackTrace();
}
}else{
//By calling this method and empty database will be created into
the default system path
//of your application so we are gonna be able to overwrite that
database with our database.
this.getReadableDatabase();
Log.d("Exception", " in copy database of cretae ");
try {
_context.openOrCreateDatabase(DB_NAME, 0, null);
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each
time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
//checkDB = _context.openOrCreateDatabase(DB_NAME, null,
SQLiteDatabase.OPEN_READWRITE);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just
created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
try {
//Open your local db as the input stream
Log.d("Exception", " in copy database
"+_context.getAssets().list("databases").length);
String[] str = _context.getAssets().list("databases");
/* for(int i = 0 ; i < str.length; i++){
Log.d("Exception", " i "+i+" "+str[i]);
}*/
InputStream myInput =
_context.getAssets().open("databases/"+DB_FILE_NAME);
// Log.d("Exception", " in copy database
"+myInput.available());
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// Log.d("Exception", " in copy database output file
"+myOutput.toString());
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public void openDataBase() throws SQLException{
//Open the database
try {
String myPath = DB_PATH + DB_NAME;
_database = _context.openOrCreateDatabase(DB_NAME,
SQLiteDatabase.OPEN_READWRITE, null);
} catch (Exception e) {
Log.d("Exception", " error in opening database "+e.toString());
e.printStackTrace();
}
}
@Override
public synchronized void close() {
if(_database != null)
_database.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
{
}
public Cursor getCursorForAllNames(){
Cursor c = null;
try {
String selectQuery = "SELECT id, name, surname, gender, designation FROM
"+NAME_MASTER_TABLE;
if(_database != null){
if(_database.isOpen()){
Log.d("NAMES_BABY", " open database ");
c = _database.rawQuery(selectQuery, null);
//c = _database.query(NAME_MASTER_TABLE, strColumns,
null, null, null, null, null);
int cnt = c.getColumnCount();
Log.d("NAMES_BABY", " getCursorForAllNames column count
"+cnt);
String[] str1 = new String[cnt];
int[] columnIds = new int[cnt];
for(int i = 0; i < cnt; i++){
str1[i] = c.getColumnName(i);
columnIds[i] = c.getColumnIndex(str1[i]);
Log.d("LOGS", " getCursorForAllNames column "+i +"
"+str1[i]);
}
}
}
}catch(Exception ex){
ex.printStackTrace();
}
return c;
}
I am getting error as java.lang.IllegalArgumentException: column '_id' does
not exist
Can anybody help me out? How to solve this error.
--
Thanks & Regards,
Renuka
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